#include <stdio.h>   
#define mx 500010    
long long i,n,a,b;   
long pi[mx];
long long x[mx];   
  
void prefix()   
{   
    long long p,i;   
    pi[1]=0;   
    p=0;   
    for (i=2; i<=n; i++)   
    {   
        while (p>0 && x[i]!=x[p+1])   
            p=pi[p];   
        if (x[i]==x[p+1])   
            p++;   
        pi[i]=p;   
    }   
}   
  
int main()   
{   
    freopen("reguli.in","r",stdin);   
    freopen("reguli.out","w",stdout);   
    scanf("%lld",&n);
	scanf("%lld",&a);
    for (i=1; i<n; i++)
	{
        scanf("%lld",&b);  
        x[i]=b-a;
		a=b;
	}
	n--;
    prefix();   
    printf("%lld\n",n-pi[n]);   
    for (i=1; i<=n-pi[n]; i++)   
        printf("%lld\n",x[i]);   
    fclose(stdin);   
    fclose(stdout);   
    return 0;   
}